[Effectiveness of early dipyrone administration on severity of dengue virus infection in a prospective cohort].

OBJECTIVE: To evaluate the impact of dipyrone administration in the first days of the disease on the severity of dengue infection.

MATERIALS AND METHODS: Prospective cohort study in adults (> 12 years) with dengue virus infection, confirmed by specific IgM titers in paired samples or isolation of the virus. The patients were enrolled in the first 96 hours of the disease. Basic demographic details, symptoms, drugs received and examination findings were recorded at admittance. A detailed clinical examination and hematocrit determination were done every day by a member of the study team until day 7 of disease. Platelet count was performed at baseline and with the development of spontaneous bleeding or evidence of plasma leakage. The association between dipyrone use in the first 96 hours of disease and the risk of dengue hemorrhagic fever (DHF) was evaluated.

RESULTS: Seven of the 110 patients enrolled developed DHF. At admission, 17 patients had received dipyrone and administration of this drug was not related to the clinical manifestations of dengue, or the use of other medication. Dipyrone was associated with an increased risk of presenting DHF (RR = 7.29; 95% CI: 1.79-29.34; P = 0.0016). Minimum platelet count in the dipyrone group (median: 105,588.2 plat/microl), was significantly smaller than that of the control group (median: 145,698.9 plat/microl): difference = 40,110.69 plat/microl; 95% CI: 1597.36-78,624.02; P = 0.0414.

CONCLUSIONS: Our data suggest that early administration of dipyrone in patients with disease caused by dengue virus is associated with lower platelet counts and an increased risk of developing DHF.